Molded expanded polystyrene (EPS) is a rigid cellular plastic that is made from expandable polystyrene pellets (or "beads") which contain a blowing agent (pentane) which is very similar to propane or butane.  It is commonly used for packaging food, medical supplies, electrical consumer goods and insulation for buildings .Then there's always the coffee cup too...

EPS is a thermoplastic polymer based on styrene, (which also occurs naturally in products such as strawberries and coffee beans.) It does not, and never has contained CFCs or HCFCs. The small proportion of hydrocarbon blowing agent used readily decomposes in the atmosphere, and as a result EPS does not have any adverse impact on the ozone layer.

Molded eps plays an important part in our daily lives.  Click this link A fresh idea... to see more...

Is eps really mostly air?  Yes, more than 95% air and less than 5% actual plastic.  The pictures below (of molded eps parts, beads and cells) clearly demonstrate that!   

On the left you see a standard molded eps end cap.  On the right is a section of that same part.  You can see the fused beads and if you look carefully you can just make out the cells within each bead.

Now (below) you're actually looking into the cells of the bead!  These are all the cells in one of the beads from the upper right-hand picture. Here it's easy to see that (and why) molded foam is mostly air.

Do you need more help? Just choose:  email us, call us or find us (after following any of these links just click the "back" button on your browser to return here).